I had a job where I answered the phone a lot and callers would say this to me on EVERY call. I would always make a joke, like, “must be Monday morning, haha.” Interestingly, I changed jobs to one where I was helping people with disability accommodations, and at that job NO caller ever joked about my stutter a single time, which was awesome. In fact I think it helped the callers be less anxious about their own speech issues, whether it was caused by a stutter, Tourette’s, a stroke, cerebral palsy, whatever.